Guo Caixin, Boullanger Paul, Jiang Long, Liu Tao
Key Laboratory of Colloid and Interface Science, Center for Molecular Science, Institute of Chemistry, Chinese Academy of Science, Beijing 100080, PR China.
Biosens Bioelectron. 2007 Mar 15;22(8):1830-4. doi: 10.1016/j.bios.2006.09.006. Epub 2006 Oct 11.
In this paper, an improved method for detection of Concanavalin A (Con A) with label-free optical biosensors is reported. 1-Dodecanethiol (DDT) was self-assembled onto gold nanoparticles which were deposited on glass slides, and then glycolipid molecules were inserted into dodecanethiol by physical interactions only. The recognition between Con A and carbohydrate was observed by UV-vis spectrophotometry. The absorption spectrum shifted when Con A was bound to the sugar residues of glycolipids immobilized onto nanogold slides, while almost no spectrum change was observed when another nonspecific protein molecule met the nanogold slides. The self-assembled bilayer on nanogold substrates had very high sensitivity for Con A, the minimum detection concentration of Con A can be down to 0.1 nM. In addition to the ultra sensitivity for investigating carbohydrate-lectin interaction, the self-assembled bilayer structure, is expected to replace many receptors which require time-consuming organic syntheses for the fixation to the transducer. The simplicity and sensitivity of this biosensor architecture once again show the prospect of nanogold application in biosensor.
本文报道了一种利用无标记光学生物传感器检测伴刀豆球蛋白A（Con A）的改进方法。将1-十二烷硫醇（DDT）自组装到沉积在载玻片上的金纳米颗粒上，然后仅通过物理相互作用将糖脂分子插入十二烷硫醇中。通过紫外可见分光光度法观察Con A与碳水化合物之间的识别作用。当Con A与固定在纳米金载玻片上的糖脂的糖残基结合时，吸收光谱发生移动，而当另一种非特异性蛋白质分子与纳米金载玻片接触时，几乎没有光谱变化。纳米金基底上的自组装双层对Con A具有非常高的灵敏度，Con A的最低检测浓度可低至0.1 nM。除了对研究碳水化合物-凝集素相互作用具有超高灵敏度外，自组装双层结构有望取代许多需要耗时的有机合成才能固定到换能器上的受体。这种生物传感器结构的简单性和灵敏度再次展示了纳米金在生物传感器中的应用前景。
